This disclosure relates to force-clamp spectrometers and force-clamp spectroscopy techniques.
The intersection of force and chemistry has been studied for over a century, yet not much is known about this phenomenon compared with more common methods of chemical catalysis. There are a number of reasons for this discrepancy, but one of the most important factors remains that it is quite difficult to directly measure the effect of force on a bulk reaction. This difficulty arises because an applied force is not a scalar property of a system; it is associated with a vector. As a result, it is often not possible to directly probe the effect of force on a particular reaction because of heterogeneous application of force and a distribution of reaction orientations (Beyer, M. K. & Clausen-Schaumann, H. (2005) Chem. Rev. 105, 2921-2948). To fully quantify the effect of an applied force on a chemical reaction, it is necessary to generate an experimental system where the reaction of interest is consistently oriented with respect to the applied force.
The direct manipulation of single molecules allows for the application of force in a vector aligned with the reaction coordinate (Evans, E. & Ritchie, K. (1997) Biophys. J. 72, 1541-1555), avoiding the heterogeneity of bulk studies. Earlier works using single molecule techniques have described the rupture forces necessary to cleave single covalent bonds, including Si—C bonds in polysaccharide attachment (Grandbois, M., Beyer, M., Rief, M., Clausen-Schaumann, H. & Gaub, H. E. (1999) Science 283, 1727-1730), Au—Au bonds in nanowires (Marszalek, P. E., Greenleaf, W. J., Li, H., Oberhauser, A. F.&Fernandez, J. M. (2000) Proc. Natl. Acad. Sci. USA 97, 6282-6286; Rubio-Bollinger, G., Bahn, S. R., Agrait, N., Jacobsen, K. W. & Vieira, S. (2001) Phys. Rev. Lett. 87, 026101), and Ni2+-NTA attachments (Conti, M., Falini, G. & Samori, B. (2000) Angew. Chem. Int. Ed. 39, 215-218).
However, these studies have not been able to describe the effect of force on the dynamics and kinetics of these reactions, nor have they examined more complex chemical reactions beyond simple bond rupture.
Accordingly, there is a need in the art for devices and methods to describe the effect of force on the dynamics and kinetics of these reactions, and to examine more complex chemical reactions beyond simple bond rupture.